— More than a decade before former Penn State coach Jerry Sandusky was charged with more than 50 counts of child sex abuse, a psychologist warned university police that his actions fit that of a “likely pedophile’s pattern.”

The finding by State College, Pa., psychologist Dr. Alycia A. Chambers, the therapist for one of Sandusky’s alleged victims, was contained in the internal Penn State files of a 1998 police investigation of the former coach for showering and bear hugging her client and another young boy in the school’s athletic locker room.

NBC News has obtained the complete file on the investigation – the police report and assessments by two psychologists who interviewed the boys -- which provides new details about Sandusky’s behavior. It also could raise fresh questions about how school and local authorities handled his case.

“There was very little doubt in my mind (Sandusky) … was a male predator, someone that was in the process of grooming a young man for abuse ,” said Chambers, speaking publicly for the first time, with the permission of her client’s family, in an interview with NBC News. “I thought…my report was strong enough to suggest that this was somebody who should be watched.”

Chambers’ detailed report is potentially significant because it was the first clear warning about the former Penn State coach’s actions – nearly four years before a then-graduate assistant, Mike McQueary, reported to the late Coach Joe Paterno and other top school officials that he had found Sandusky in the Penn State showers one evening with another young boy, engaged in what he viewed as sexual contact. (Paterno testified last year he was unaware of the 1998 investigation and Gary Schultz, the former Penn State vice president who oversaw the school police, testified that he never reviewed the details of the case. A Penn State spokesman declined comment, citing pending investigations.)

In her interview with NBC News, Chambers described her anguish when she was contacted by police last year and learned that authorities were again investigating Sandusky for allegedly molesting multiple other boys, 13 years after she first raised her concerns.

“I was horrified to know that there were so many other innocent boys who had their hearts and minds confused, their bodies violated,” said Chambers. “It’s unspeakable.”

Joe Amendola, Sandusky’s lawyer, said he hasn’t seen Chambers’ report, but that her conclusions will be disputed by other psychologists who will be called by the defense. “I understand that there are some people who could look at this behavior and say it’s a pedophile problem. But there are others who will say, ‘This is somebody who loves kids and loves to be around them’ … It’s the old story, you get your expert and I’ll get my expert.” Sandusky has pleaded not guilty to all charges.

But one of the investigators on the 1998 case, Jerry Lauro, then with the state Department of Public Welfare and now retired, told NBC News he was never shown a copy of Chambers’ report and was stunned to learn of its conclusions.

“Wow!” he said when he was read Chambers’ conclusions by a NBC News correspondent. “This is the first I’ve heard of this. I had no idea . If I would have seen the report, I would certainly have done some things differently. Boy, this is a shock. “

Chambers was the psychologist for a then-11- year-old boy, who had met Sandusky through his Second Mile charity for troubled children and was later invited by the defensive coordinator to several Penn State football games. The boy is now known as Victim 6—one of 10 allegedly molested by Sandusky and one of the key figures in the criminal case against him slated to go to trial this spring. Amendola this week asked a judge to drop Victim 6 from the case on the grounds that his anticipated testimony “will not establish that any sexual contact took place.”

The police file provides a fuller picture than has been previously made public about Sandusky’s interactions with the boy as well as the transcripts of two tense confrontations between Sandusky and the boy’s mother. Chambers was called by the boy’s mother at 7:43 a.m. on May 4, 1998. The boy had returned home the night before, his hair wet, after spending two hours with Sandusky at the Penn State athletic room. After meeting with her client in her office and talking to his mother, Chambers described in her written report how Sandusky had coaxed the boy into the shower after a workout, telling him, “All the guys do.” He then moved closer to him, squeezing him tightly from behind while they were both naked. The boy also told Chambers how, during their workout, Sandusky had kissed him on the forehead and told him, ‘I love you.” He also invited the boy back to his house to “sit on his lap” and go “online” on his “cool computer,” the boy’s mother told Chambers, recounting her conversation with her son the previous night.

“My consultants agree that the incidents meet all of our definitions, based on experience and education, of a likely pedophile’s pattern of building trust and gradual introduction of physical touch, within a context of a ‘loving,’ ‘special’ relationship,” Chambers wrote in her report.

“One colleague, who has contact with the Second Mile, confirms that Mr. Sandusky is reasonably intelligent and thus, could hardly have failed to understand the way his behavior would be interpreted, if known,” Chambers continued. “His position at the Second Mile and his interest in abused boys would suggest that he was likely to have had knowledge with regard to child abuse and might even recognize this behavior as a typical pedophile ‘overture.’”

Chambers gave her report to Penn State police Officer Ronald Schreffler on May 7, 1998, along with a cover letter that highlighted “the gravity of the incidents.” Chambers had also reported the incident to the Pennsylvania “suspected child abuse” hotline, where officials wrote up their own report identifying Sandusky as the “AP” or “Alleged Perpetrator.” Lauro, an investigator who specialized in abuse cases, was assigned to work the case with Schreffler.

Investigators brought in a second psychologist, John Seasock, who had worked with the local Centre County Child and Youth Services, a local agency that had licensed Sandusky as a foster parent. After meeting with the boy for an hour, Seasock concluded that no sexual offense had taken place nor was there “grooming” or “inappropriate sexual behavior” by Sandusky.

”All the interactions reported by (the boy) can be typically defined as normal between a healthy adult and a young adolescent male,” Seasock wrote in his report.

Lawyer: Report helps defense Amendola, Sandusky’s lawyer, has said that he hopes to use Seasock’s report in his client’s defense. But the police files show that Seasock conducted his interview of the boy “cold,” without reviewing Chambers’ report or prior transcripts of interviews with the boy and that he failed to elicit some key details, such as Sandusky kissing the boy and telling him, “I love you.”

Seasock acknowledged to police there were some “gray areas” and that investigators “can’t walk away from the investigation.” But he also appeared to dismiss most of the concerns that had been raised about Sandusky in an interview with investigators.

“SEASOCK said that he hasn’t heard of a 52-year-old becoming a pedophile,” the police report states. “SEASOCK said that SANDUSKY didn’t fit the profile of a pedophile.” (Asked by police if it was "possible" that a man that age could become a pedophile, he replied it was "possible.”)

The Penn State police file shows that investigators continued to pursue the case under the supervision of the late Ray Gricar, then the local district attorney. According to the police report, they interviewed a second boy – a friend of Victim 6 — who also described being “uncomfortable” when Sandusky hugged him in the Penn State showers.

In the days following Chambers’ interview with the boy, the mother became concerned because Sandusky was continuing to call her son at his apartment, coming by the back of the family’s apartment with rear sliding doors and even showing up at a ball field where her son had Little League practice. As Sandusky continued to try to contact the boy, the police hid in the bedroom of the family’s apartment and monitored two confrontations between the mother and Sandusky.

On the afternoon of May 13, 1998, Sandusky knocked on the door of the family home, looking for the boy. The mother greeted him instead, telling him ever since her son had seen him the previous week, “he’s been acting different. He won’t talk and he’s been having nightmares.”

When Sandusky asked to talk to her son, the mother replied: “I don’t want you calling here for (her son.) I need to think about this. Let me call you if it’s OK to pick (her son) up.

“Maybe I worked him too hard,” Sandusky replied.

“Did something happen?” the boy’s mother asked.

“I don’t think so,” replied Sandusky.

On May 19, police arranged to monitor a second meeting that turned even more tense and resulted in Sandusky having “tears in his eyes,” according to the mother’s account to investigators.

Sandusky: “Yes.”The mother recounted how “you told him you loved him and kissed him on the head.” Sandusky replied that the boy “told me he loved me, so I told him the same thing.”

The mother said her son had looked at Sandusky “as a hero, a father figure, he is really confused.”Sandusky then pressed to talk to the boy again, but the mother told him that would not be a “good idea.” “I don’t want you going to (his) ball games.”

“I understand,” Sandusky replied. “I was wrong. I wish I could get forgiveness. I know I won’t get it from you. I wish I were dead.”

Just a week and a half later, the two lead investigators —Schreffler and Lauro—interviewed Sandusky at his office at the Penn State athletic building. He acknowledged that he hugged the boy in the shower “but that there wasn’t anything sexual about it.” He also said that he had showered with other boys and “realized he used poor judgment in what he did.”

“As a result of the investigation, it could not be determined that a sexual assault occurred and Sandusky was advised of such, “the police report reads. One of the investigators then “advised SANDUSKY not to shower with any child. SANDUSKY stated that he wouldn’t.”

“CASE CLOSED,” the file reads.

There are no reasons given in the report for why Gricar ultimately chose not to prosecute Sandusky based on the 1998 investigation. (In a case that remains open, Gricar disappeared in 2005 and is now presumed dead. Investigators say there is no indication his disappearance relates to Sandusky.)

In an in an interview with NBC News, the boy’s mother described telling her son that night that no charges would be brought against Sandusky.

Her son, she said, was “confused.”

“I don’t understand, Mommy,” she said he replied. “I’m just a little kid. I knew what he did was wrong. Why didn’t he (know it was wrong)?”

Sandusky retired from Penn State the following year — to spend more time working with Second Mile, he said. But he was made a “professor emeritus” and maintained keys to the Penn State locker room, where he continued to take young boys to the showers. In a telephone interview Friday, Amendola was asked why Sandusky still showered with young boys after 1998 when police had told him not to —and he told them he wouldn’t.

“He viewed that more as an admonition, not an order,” Amendola said. “He didn’t think there was anything wrong with it.” Amendola added that Sandusky “never thought that the situation in ‘98 was a big deal. He never looked at as that serious.”

“It’s very disturbing,” said Walter Cohen, a former Pennsylvania attorney general in the mid-1990’s, who reviewed parts of the Penn State police file, including Chambers’ report, at NBC News request. “It never should have been ignored. Never.”

As a former secretary of public welfare in the 1980s, Cohen had set up a statewide “child-line” registry of suspected child abusers that could serve as a central data base for school officials and others working with children to conduct background checks on prospective employees. Even if there were no criminal charges brought, Cohen said, there was more than enough evidence to have placed Sandusky on the statewide registry.

“Jerry Sandusky should have been on the watch list,” he said. “But instead, the case was closed.”